US7352119B2ExpiredUtilityA1
Method for designing a discharge lamp
Assignee: PATENT TREUHAND GES FUER ELEKTRISCHE GLUEHLAMPEN MBHPriority: Jul 2, 2004Filed: Jul 1, 2005Granted: Apr 1, 2008
Est. expiryJul 2, 2024(expired)· nominal 20-yr term from priority
Inventors:Henning Rehn
F21V 7/04H04N 9/315
62
PatentIndex Score
4
Cited by
3
References
4
Claims
Abstract
The invention relates to a method for designing a discharge lamp for use with a light-gathering system, in particular of a projector for data or video projection. Also disclosed are a lamp designed using such a method and a reflector provided therefore.
Claims
exact text as granted — not AI-modified1. A projector lamp assembly comprising:
a double ended high intensity arc discharge lamp burner having an axis and a body defining a vessel with an enclosed volume and an axially aligned first electrode and second electrode each electrode having an internal tip, the first electrode tip and second electrode tip having a separation distance of g and having a midpoint axially between the tips and an axial distance from the midpoint to an end of the body of L;
an reflector having a reflective surface in the form of a portion of an ellipsoid of revolution with an eccentricity of e 0 , a major semiaxis distance of a, a minor semiaxis of b, a first focal point F 1 and a second focal point F 2 , the first focal point F 1 and the second focal point F 2 being axially aligned with the lamp with the first focal point F 1 being positioned at the midpoint of the lamp;
and an optical transmission structure having an optical input positioned relative to the reflector to locate the input at the second focal point F 2 , the optical transmission structure having an etendue of E and an acceptance angle of γ′; wherein
e 0 =e a (γ′)−Δ e (γ′, E,g ) equation 3
e
a
=
2
+
1
-
tan
γ
′
2
2
+
1
+
tan
γ
′
2
equation
1
and
Δ
e
=
1.3
sin
2
γ
′
exp
(
-
2
E
0.17
g
)
.
equation
2
2. The lamp assembly in claim 1 , in which the axial distance from the reflector surface to the first focal point F 1 (focal length (f 1 )) is selected to be greater than 8 mm.
3. The lamp assembly in claim 1 , in which the axial distance from the reflector surface to the second focal point F 2 (longer focal length (f 2 )) is determined according to
f
2
=
L
+
d
4
[
2
+
1
m
-
m
2
+
1
]
1
-
m
,
equation
4
where
m
=
1
-
e
o
1
+
e
o
=
f
1
f
2
,
equation
5
and the ellipse semiaxes (a, b) are calculated therefrom according to
a
=
f
2
1
+
e
o
equation
6
b
=
a
1
-
e
o
2
.
equation
7
4. The lamp assembly in claim 1 , in which the axial distance from the reflector surface to the second focal point F 2 , (longer focal length (f 2 )) is determined according to
f
2
=
1
1
-
m
[
L
+
d
2
(
2
+
1
m
-
m
2
+
1
)
-
2
tan
ξ
2
+
(
2
+
1
m
-
m
2
+
1
)
tan
ξ
]
,
equation
8
where
m
=
1
-
e
o
1
+
e
o
=
f
1
f
2
and
0
≤
ξ
≤
2
°
equation
5
and the ellipse semiaxes (a, b) are calculated therefrom according to
a
=
f
2
1
+
e
o
equation
6
b
=
a
1
-
e
o
2
.
equation
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